A class action lawsuit filed today by the ACLU, along with the Prison Law Office, the Arizona Center for Disability Law, and the law firms Jones Day and Perkins Coie, alleges that the Arizona Department of Corrections (ADC) houses thousands of prisoners in solitary confinement conditions so harsh they violate the Eighth Amendment ban on cruel and unusual punishment. While other states also use solitary confinement, Arizona has added features that seem designed to gratuitously increase suffering. The cells in that state's supermax Special Management Units (SMUs) were deliberately constructed with no windows to the outside, so prisoners — many of whom have no means of telling the time — become disoriented and confused, not knowing the whether it is day or night. The cells are often illuminated 24 hours a day, making sleep difficult and further contributing to prisoners' disorientation and mental deterioration.

Some prisoners in solitary spend all but six hours a week alone in their cells. Their only respite occurs when they are taken to a slightly larger windowless cell, with no equipment, for "exercise." Many prisoners refuse to go, because the cell is so small that it doesn't allow meaningful exercise, and because prisoners are placed in restraints and strip-searched when going to and returning from the cell. And in a final cruelty, ADC reasons that because prisoners in solitary don't get much exercise, they don't need much food — some receive only two meals a day.

It's long been known that solitary confinement is extraordinarily damaging to mental health, often inducing mental illness in previously healthy prisoners. But it's particularly damaging to those with pre-existing mental illness. For these prisoners, solitary poses a grave risk of psychiatric injury, self-harm, and even suicide. Deprived of the social interaction that is essential to keep them grounded in reality, many prisoners with mental illness experience catastrophic and often irreversible psychiatric deterioration.

Courts have ruled that prisoners with mental illness suffer such grievous harm in solitary confinement that it violates the Eighth Amendment to house them there. One court compared putting a person with mental illness in solitary to "putting an asthmatic in a place with little air to breathe." As a result, many states that use solitary confinement exclude the mentally ill. But not Arizona — even prisoners whom ADC itself has classified as "seriously mentally ill" are held in solitary.

In recent years, states as diverse as Mississippi, Colorado, and Maine have reduced their use of solitary confinement, generating substantial cost savings and experiencing no adverse effects on public safety. But Arizona remains an enthusiastic practitioner, with four large prisons devoted chiefly or exclusively to holding prisoners in solitary.

Last month Illinois Gov. Pat Quinn announced plans to close Tamms Correctional Center, that state's supermax prison. Tamms has long been criticized for its harsh conditions of solitary confinement — a federal judge found that it inflicts "lasting psychological and emotional harm" on prisoners — and the per-prisoner cost of Tamms is three times the state average. Arizona should follow Illinois' example. It would be a victory for fiscal prudence as well as human rights.